Main Features: 1. Accurate active energy measurement for long-term operation without calibration under normal operation condition; 2. Using software spread spectrum communication technology to implement interconnection between the devices over the power lines; achieving automatic meter reading with accurate and reliable performance; 3. Automatically repeat relaying communication each other, wonderful communication ability, high success rate of meter reading; 4. Measure positive, negative active energy (negative energy can be counted into positive energy); 5. Broad dynamic operation range, actual overload capability up to 10times. Excellent error linearity within the range of 1%Ib～Imax; 6. Excellent anti-tamper capability: by adopting anti-magnetism and anti-reverse counter combed with special circuit design 7. Adopting world famous, long-life and high reliability components ensure it has the characteristics of long-life and high reliability; 8. Provided both photo-electric insulated impulse test output and LED test output for the customers' convenience of test choosing;